

#include <stdio.h>
#include <unistd.h>
#include <sys/types.h>
int main()
{
    pid_t id = fork();
  if(id == 0)
  {
    while(1)
    {
      printf("子进程pid %d ppid %d",getpid(),getppid());
      fflush(stdout);
      sleep(1);
    }
  }
  else if(id > 0)
  {
    while(1)
    {
      printf("父进程pid %d ppid %d",getpid(),getppid());
      fflush(stdout);
      sleep(1);
    }
  }

}
  
